create field on account and made chagnes

Example 2:-

The following trigger updates the field called “Hello” by the value “World”whenever we are creating an account or updating an account record. Create the field called “Hello” on the Account Object (Data Type = Text)


Trigger updateHello on Account (Before Insert , Before Update){
  switch on Trigger.operationType{
   when BEFORE_INSERT {
    updateHelloHelper.updateHelloToWorld(Trigger.new);
   }
   when BEFORE_UPDATE{
   updateHelloHelper.updateHelloToWorld(Trigger.new);
   }
  }
}

public with sharing class updateHelloHelper {
  public static void updateHelloToWorld(List<Account> accLst){
  if(accLst != null){
  List<account> accUpdate = new List<account>();
  for(Account acc : accLst){
  List<account> accQ = [select, id, name, hello from account];
  acc.Hello = 'World';
  accUpdate.add(acc);
  }
  INSERT accUpdate;
  }
  }
}